Battery capacity detection method, battery capacity detection system, computer equipment and storage medium

Abstract

The invention relates to the technical field of battery capacity detection, and discloses a battery capacity detection method, a battery capacity detection system, computer equipment and a storage medium, and the method comprises the steps: detecting the capacitance value of a battery cell; calculating and determining the opposite area of a positive plate and a negative plate in the battery cell based on the capacitance value; and calculating and determining the calculated capacity of the battery cell based on the opposite area. According to the method, the capacitance value of the battery cell is detected, then the opposite area of the positive plate and the negative plate in the battery cell is calculated based on the capacitance value, and then calculation is performed based on the opposite area, so that the calculated capacity of the battery cell can be finally determined, and relatively high detection accuracy can be ensured; and moreover, the detection time is greatly shortened without charging and discharging the battery cell, the detection cost is low, and wide production, popularization and application of the battery are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of battery capacity detection, and particularly to a battery capacity detection method, a battery capacity detection system, a computer device, and a storage medium. Background Art

[0002] In the field of batteries, lithium-ion batteries (referred to as lithium batteries for short) have become the core energy supply components of portable electronic devices, such as computers, mobile phones, etc., due to their advantages of high output voltage, high specific capacity, high safety, etc., and are gradually occupying a dominant position in the energy systems of electric vehicles (EVs) and hybrid electric vehicles (HEVs).

[0003] After the capacity test is completed, the batteries need to go through a screening process. Subsequently, these screened batteries are combined in series or in parallel to form a battery module or a battery pack. The consistency of the capacities between the batteries inside the battery module or the battery pack has a direct impact on the capacity release efficiency and service life of the entire battery pack. Therefore, the capacity parameter of the battery is regarded as an important and indispensable indicator in the battery management and maintenance process. Specifically, the higher the consistency of the capacities between the batteries, the better the performance of the battery module or the battery pack.

[0004] Currently, a method for detecting the capacity of a battery is the direct discharge method. The direct discharge method is to fully charge the battery to a full charge state, and then use a discharge device to completely deplete the battery power, and record the cumulative released power value during the entire discharge cycle. This power value represents the actual capacity of the battery. Although this method has high accuracy in estimating the battery capacity, it requires the assistance of a charging device and takes a long time.

[0005] Therefore, it is particularly important to develop a new battery capacity detection method to overcome the defects of the existing methods.

[0006] The above information is given as background information only to assist in understanding the present disclosure, and it is not determined or admitted whether any of the above content can be used as the prior art relative to the present disclosure. Summary of the Invention

[0007] The present invention provides a battery capacity detection method, a battery capacity detection system, a computer device, and a storage medium to solve the problems of inaccurate battery capacity detection and long time consumption in the existing technology.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] In a first aspect, the present invention provides a battery capacity detection method, and the method includes:

[0010] Detect the capacitance value of the battery cell;

[0011] Based on the capacitance value, calculate and determine the facing area between the positive electrode plate and the negative electrode plate in the battery cell;

[0012] Based on the facing area, calculate and determine the calculated capacity of the battery cell.

[0013] Further, in the battery capacity detection method, the step of calculating and determining the facing area between the positive electrode plate and the negative electrode plate in the battery cell based on the capacitance value includes:

[0014] Obtain the dielectric constant of the medium between the positive electrode plate and the negative electrode plate in the battery cell; obtain the distance between the positive electrode plate and the negative electrode plate in the battery cell; and calculate and determine the facing area between the positive electrode plate and the negative electrode plate in the battery cell according to the following formula:

[0015] ;

[0016] Wherein, is the capacitance value of the battery cell; is the dielectric constant of the medium between the positive electrode plate and the negative electrode plate in the battery cell; is the facing area between the positive electrode plate and the negative electrode plate in the battery cell; is the electrostatic constant; is the distance between the positive electrode plate and the negative electrode plate in the battery cell.

[0017] Further, in the battery capacity detection method, the step of calculating and determining the calculated capacity of the battery cell based on the facing area includes:

[0018] Obtain the coating surface density of the positive electrode plate in the battery cell; and calculate and determine the measured capacity of the battery cell according to the following formula:

[0019] ;

[0020] Wherein, is the measured capacity of the battery cell; is the facing area between the positive electrode plate and the negative electrode plate in the battery cell; is the coating surface density of the positive electrode plate in the battery cell.

[0021] Further, in the battery capacity detection method, the step of detecting the capacitance value of the battery cell includes:

[0022] Electrically connect the capacitance test equipment to the positive electrode tab and the negative electrode tab of the battery cell respectively, and then control the capacitance test equipment to work.

[0023] Further, in the battery capacity detection method, the method further includes:

[0024] Based on the following relationship among the corrected capacity, the weight of the battery cell, and the calculated capacity, correct the calculated capacity to obtain the corrected capacity of the battery cell:

[0025] ;

[0026] Wherein, is the corrected capacity of the battery cell; is the calculated capacity of the battery cell; is the weight of the battery; 、 are constants; is the capacity compensation coefficient.

[0027] Further, in the battery capacity detection method, the method further includes:

[0028] Prepare multiple sample battery cells, and measure and obtain the weight and capacity of the battery cells in a laboratory environment;

[0029] Obtain the capacities of multiple sample battery cells with different weights of the battery cells, and fit the capacity of the battery cells and the weight of the battery cells to obtain a relationship: y = Am + B, where y is the capacity of the battery cell, m is the weight of the battery cell, and A and B are constants;

[0030] Obtain the capacities of multiple sample battery cells with the same weight of the battery cells, and calculate the average value of the capacities of the battery cells to obtain D;

[0031] Through the formula Get, where, , ;

[0032] Through the formula Get, to construct a relationship among the corrected capacity, the weight of the battery cell, and the capacity of the battery cell, where, is the corrected capacity, is the capacity of the battery cell, and c is the capacity compensation coefficient.

[0033] In a second aspect, the present invention provides a battery capacity detection system, which includes a capacitance detection module, an area calculation module, and a capacity calculation module;

[0034] The capacitance detection module is used to detect the capacitance value of the battery cell;

[0035] The area calculation module is used to calculate and determine the facing area of the positive electrode plate and the negative electrode plate in the battery cell based on the capacitance value;

[0036] The capacity calculation module is configured to:

[0037] Determine the calculated capacity of the battery cell based on the calculated positive facing area.

[0038] Further, in the battery capacity detection system, the area calculation module is specifically configured to:

[0039] Obtain the dielectric constant of the medium between the positive electrode plate and the negative electrode plate in the battery cell; obtain the distance between the positive electrode plate and the negative electrode plate in the battery cell; and calculate and determine the positive facing area between the positive electrode plate and the negative electrode plate in the battery cell according to the following formula:

[0040] ;

[0041] Wherein, is the capacitance value of the battery cell; is the dielectric constant of the medium between the positive electrode plate and the negative electrode plate in the battery cell; is the positive facing area between the positive electrode plate and the negative electrode plate in the battery cell; is the electrostatic constant; is the distance between the positive electrode plate and the negative electrode plate in the battery cell.

[0042] Further, in the battery capacity detection system, the capacity calculation module is specifically configured to:

[0043] Obtain the coating surface density of the positive electrode plate in the battery cell; and calculate and determine the calculated capacity of the battery according to the following formula:

[0044] ;

[0045] Wherein, is the calculated capacity of the battery cell; is the positive facing area between the positive electrode plate and the negative electrode plate in the battery cell; is the coating surface density of the positive electrode plate in the battery cell. Further, in the battery capacity detection system, the capacitance detection module is specifically configured to:

[0046] Electrically connect the capacitance test equipment to the positive electrode tab and the negative electrode tab of the battery cell respectively, and then control the capacitance test equipment to work.

[0047] Further, in the battery capacity detection system, the system further includes a capacity correction module for:

[0048] Correct the calculated capacity based on the following relationship among the corrected capacity, the battery cell weight, and the calculated capacity to obtain the corrected capacity of the battery cell:

[0049] ;

[0050] Wherein, is the corrected capacity of the battery cell; is the calculated capacity of the battery cell; is the weight of the battery cell; , are constants; is the capacity compensation coefficient.

[0051] Further, in the battery capacity detection system, the system further includes a relationship construction module for:

[0052] Preparing a plurality of sample battery cells and measuring and obtaining the weight and capacity of the battery cells in a laboratory environment;

[0053] Obtaining the capacities of a plurality of sample battery cells with different weights of the battery cells, and fitting the capacity of the battery cell and the weight of the battery cell to obtain a relationship: y = Am + B, where y is the capacity of the battery cell, m is the weight of the battery cell, and A and B are constants;

[0054] Obtaining the capacities of a plurality of sample battery cells with the same weight of the battery cells, and calculating the average value of the capacities of the battery cells to obtain D;

[0055] Through the formula obtain , wherein , ;

[0056] Through the formula obtain , so as to construct a relationship among the corrected capacity, the weight of the battery cell, and the capacity of the battery cell, wherein is the corrected capacity, is the capacity of the battery cell, and c is the capacity compensation coefficient.

[0057] In a third aspect, the present invention provides a computer device, including a memory and a processor, where the memory stores a computer program, and when the processor executes the computer program, it implements the battery capacity detection method provided in the first aspect as described above.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] A battery capacity detection method, a battery capacity detection system, a computer device, and a storage medium provided by the present invention calculate the capacitance value of a battery cell, then calculate the facing area between the positive electrode plate and the negative electrode plate in the battery cell based on the capacitance value, and then perform calculations based on the facing area, so as to finally determine the capacity of the battery cell. This not only ensures high detection accuracy, but also greatly shortens the detection time because there is no need to charge and discharge the battery cell. At the same time, the detection cost is low, which is beneficial to the wide production and popularization of batteries.

[0060] The present invention has other characteristics and advantages, which will be obvious from the accompanying drawings incorporated herein and the subsequent detailed description, or will be described in detail in the accompanying drawings incorporated herein and the subsequent detailed description. These accompanying drawings and detailed description are used together to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0062] Figure 1 is one of the schematic flowcharts of a battery capacity detection method provided in Embodiment 1 of the present invention;

[0063] Figure 2 is the second schematic flowchart of a battery capacity detection method provided in Embodiment 1 of the present invention;

[0064] Figure 3 is a schematic diagram of the relationship curve between the weight and capacity of the battery provided in Embodiment 1 of the present invention;

[0065] Figure 4 is a schematic diagram of the functional modules of a battery capacity detection system provided in Embodiment 2 of the present invention;

[0066] Figure 5 is a schematic diagram of the structure of a computer device provided in Embodiment 3 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0067] To illustrate in detail the possible application scenarios, technical principles, implementable specific solutions, achievable objectives and effects, etc. of the present application, the following will be described in detail with reference to the specific embodiments listed and in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, so they are only examples and cannot be used to limit the protection scope of the present application.

[0068] References to "embodiments" in this application mean that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The term "embodiment" appearing at various positions in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0069] Unless otherwise defined, the meanings of the technical terms used in this application are the same as those commonly understood by those skilled in the technical field to which this application belongs; the use of the relevant terms in this application is only for describing specific embodiments and is not intended to limit this application.

[0070] In the description of this application, the phrase "and / or" is an expression used to describe the logical relationship between objects, indicating that there can be three relationships. For example, A and / or B means: there is A, there is B, and there is both A and B at the same time. In addition, the character " / " in this application generally represents an "or" logical relationship between the associated objects before and after.

[0071] In this application, terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantitative, primary-secondary, or sequential relationships between these entities or operations.

[0072] Without further limitation, in this application, the use of "including", "comprising", "having" or other similar expressions in a statement is intended to cover non-exclusive inclusion. These expressions do not exclude the possibility that there may be additional elements in the process, method, or product that includes the said elements, so that a process, method, or product that includes a series of elements may include not only those defined elements, but also other elements not explicitly listed, or elements inherent to such a process, method, or product.

[0073] In this application, expressions such as "greater than", "less than", "exceeding" are understood not to include the number itself; expressions such as "above", "below", "within" are understood to include the number itself. In addition, in the description of the embodiments of this application, the meaning of "multiple" is two or more (including two), and similar expressions related to "many" are also understood in this way, such as "multiple groups", "multiple times", etc., unless otherwise specifically defined.

[0074] In the description of the embodiments of the present application, the spatially related expressions used, such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "perpendicular", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the specific embodiment or the attached drawings. It is only for the convenience of describing the specific embodiments of the present application or facilitating the understanding of the readers, rather than indicating or implying that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, it should not be construed as a limitation to the embodiments of the present application.

[0075] Unless otherwise clearly specified or limited, in the description of the embodiments of the present application, the terms such as "installation", "connection", "connection", "fixation", "setting", etc. should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two components or the interaction relationship between two components. For those skilled in the art to which the present application pertains, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0076] Embodiment 1

[0077] Please refer to Figure 1 , Figure 1 which is a schematic flow chart of a battery capacity detection method provided for Embodiment 1 of the present invention. This method is applicable to the scenario of detecting the capacity of a battery. The method specifically includes the following steps:

[0078] S101. Detect the capacitance value of the battery cell.

[0079] It should be noted that this step is the starting point of the entire battery capacity detection method. The capacitance value of the battery cell refers to the ability of the positive electrode plate and the negative electrode plate inside the battery cell to store charges. In actual operation, professional capacitance measurement equipment or instruments need to be used to measure the capacitance value between the positive electrode plate and the negative electrode plate of the battery cell in a non-invasive manner (that is, without damaging the structure of the battery cell). Specifically, the capacitance test equipment is electrically connected to the positive electrode tab and the negative electrode tab of the battery cell respectively, and then the capacitance test equipment is controlled to work. This capacitance value reflects certain characteristics of the internal structure of the battery cell and is an important basic data for calculating the capacity of the battery cell later.

[0080] It should be particularly noted that the capacitance value detection here is not the capacitance measurement of a traditional capacitance element, but uses the positive and negative electrode plates inside the battery cell as the two plates of the capacitor, and indirectly reflects certain physical characteristics of the battery cell by measuring the capacitance effect between them.

[0081] In addition, it is preferred to detect the capacitance value before injecting the electrolyte. Because at this stage, the internal structure of the battery is relatively stable and not affected by factors such as the electrolyte, the accuracy of the detection result is higher. At the same time, this also provides a more reliable reference basis for the subsequent correction of the battery capacity.

[0082] In addition, after the detection is completed, the battery is then normally filled with electrolyte and undergoes normal flowing and pulling (after infiltration, the battery will go through a charge and discharge cycle to activate the battery material and form a stable SEI film. This process is usually called "flowing and pulling" because it involves the flow of current in the battery). In the later stage, the battery does not need to be tested for capacity through charge and discharge, and the test cost and production cycle are significantly shortened.

[0083] S102. Calculate and determine the facing area between the positive electrode plate and the negative electrode plate in the battery cell based on the capacitance value.

[0084] It should be noted that after obtaining the capacitance value of the battery cell, the next step is to calculate the facing area between the positive electrode plate and the negative electrode plate in the battery cell according to the physical relationship between the capacitance value and the facing area.

[0085] Since there is a direct proportional relationship between the capacitance value between the positive electrode plate and the negative electrode plate and the facing area between the positive electrode plate and the negative electrode plate, that is, the larger the facing area, the larger the capacitance value. Therefore, after detecting the capacitance value between the positive electrode plate and the negative electrode plate of the battery, the facing area between the positive electrode plate and the negative electrode plate can be calculated and determined through the direct proportional relationship.

[0086] The calculation process of this step requires the use of the basic formula of capacitance and is carried out in combination with the specific structure and material characteristics of the battery cell. Through this step of calculation, the facing area between the positive electrode plate and the negative electrode plate inside the battery cell can be obtained, which is a key parameter for calculating the capacity of the battery cell in the follow-up.

[0087] S103. Calculate and determine the calculated capacity of the battery cell based on the facing area.

[0088] It should be noted that after obtaining the facing area between the positive electrode plate and the negative electrode plate in the battery cell, the last step is to calculate the capacity of the battery cell based on this area. The capacity of the battery cell refers to the amount of electric charge that the battery cell can store.

[0089] Since the facing area between the positive electrode plate and the negative electrode plate is an important factor in the battery capacity and is directly related to the battery capacity. In battery design, the facing area between the positive electrode plate and the negative electrode plate determines the upper limit of the amount of electric charge that can be accommodated inside the battery. When the facing area increases, the amount of electric charge that can be accommodated inside the battery will also increase accordingly, which may increase the battery capacity. That is, there is also a proportional relationship between the facing area between the positive electrode plate and the negative electrode plate and the battery capacity. Therefore, after calculating and determining the facing area between the positive electrode plate and the negative electrode plate, the battery capacity can be further calculated and determined through the proportional relationship.

[0090] It can be understood that after the battery capacity detection is completed, the consistency of the battery modules or battery packs produced after screening and grouping according to the battery capacity is good, and the performance is well exerted.

[0091] Please refer to Figure 2 , in an implementation manner of this embodiment, on the basis of Figure 1 , step S102 can be further refined to include the following sub-steps:

[0092] S1021. Obtain the dielectric constant of the medium between the positive electrode plate and the negative electrode plate in the battery cell, and obtain the distance between the positive electrode plate and the negative electrode plate in the battery cell.

[0093] It should be noted that in this sub-step, two key parameters inside the battery cell need to be obtained: one is the dielectric constant of the medium between the positive electrode plate and the negative electrode plate, which reflects the response ability of the medium to the electric field; the other is the distance between the positive electrode plate and the negative electrode plate, which determines the distribution of the electric field between the two plates. These two parameters are both necessary for subsequent calculation of the facing area.

[0094] To obtain these parameters, professional measurement equipment or instruments need to be used, or the manufacturing specifications and technical documents of the battery cell need to be referred to. In some cases, these parameters may be known or can be obtained through experimental measurement.

[0095] S1022. Calculate and determine the facing area between the positive electrode plate and the negative electrode plate in the battery cell according to the following formula:

[0096] ;

[0097] Wherein, is the capacitance value of the battery cell; is the dielectric constant of the medium between the positive electrode plate and the negative electrode plate in the battery cell; is the facing area between the positive electrode plate and the negative electrode plate in the battery cell; is the electrostatic constant; is the distance between the positive electrode plate and the negative electrode plate in the battery cell.

[0098] It should be noted that the constants and variables involved in the formula need to be determined according to specific battery materials and designs.

[0099] Please refer to again Figure 2 , in an implementation manner of this embodiment, in Figure 1 Based on this, step S103 can be further refined into the following sub-steps:

[0100] S1031. Obtain the coating surface density of the positive electrode sheet in the battery cell.

[0101] S1032. Calculate and determine the calculated capacity of the battery cell according to the following formula:

[0102] ;

[0103] Wherein, is the calculated capacity of the battery cell; is the facing area of the positive electrode sheet and the negative electrode sheet in the battery cell; is the coating surface density of the positive electrode sheet in the battery cell.

[0104] It should be noted that the constants and variables involved in the formula need to be determined according to specific battery materials and designs.

[0105] In an implementation manner of this embodiment, the method further includes:

[0106] Based on the following relationship among the corrected capacity, the weight of the battery cell, and the calculated capacity, correct the calculated capacity to obtain the corrected capacity of the battery cell:

[0107] ;

[0108] Wherein, is the corrected capacity of the battery cell, is the calculated capacity of the battery cell, m is the weight of the battery cell, a and b are constants, and c is the capacity compensation coefficient.

[0109] It should be noted that the constants and constant correction coefficients involved in the formula can be determined by fitting experimental data.

[0110] Since the capacitance value between the positive electrode and the negative electrode is not only directly proportional to the facing area between the positive electrode and the negative electrode, but also inversely proportional to the distance between the positive electrode and the negative electrode, the capacitance value detected between the positive electrode and the negative electrode of the battery is affected by the distance between the detected positive electrode and the negative electrode. Therefore, in order to minimize the influence of the distance between the positive electrode and the negative electrode on the capacitance value between the positive electrode and the negative electrode and the battery capacity, the weight of the battery is specifically introduced in this embodiment to correct the battery capacity.

[0111] Specifically, there is also a certain correlation between the capacity and the weight of the battery, and it is also a direct proportional relationship, that is, generally, the greater the weight of the battery, the greater the capacity of the battery. Therefore, after detecting the weight of the battery, the capacity of the battery can be corrected through the direct proportional relationship to obtain a more accurate capacity detection result of the battery.

[0112] For the formula used in the above correction process, the derivation process is as follows:

[0113] As Figure 3 shown, the relational expression for the correlation between the battery capacity and the battery weight is ;

[0114] Assume that the standard weight of the battery is m0 (a known fixed value), then the fitted capacity of the battery weight corresponding to it is , and the calculated value is a fixed value, set as k;

[0115] Assume that the actual weight of the battery is m, m≠m0, then the measured capacity of the battery corresponding to it is , and the measured capacity C1 is a test value;

[0116] → →

[0117] ;

[0118] Set , → → ;

[0119] Since the weight-fitted capacity C0 and the measured standard capacity distribution of the battery are not completely consistent, assuming the difference is c, the actual fitted capacity is:

[0120] ;

[0121] It is verified that the corrected battery capacity obtained from the battery weight and the capacitance value between the positive and negative electrodes has a correlation of up to 90% with the test capacity obtained from the laboratory charge and discharge test.

[0122] In an implementation manner of this embodiment, the method further includes:

[0123] (1) Prepare multiple sample battery cells and measure the weight and capacity of the battery cells in a laboratory environment;

[0124] It should be noted that in this step, multiple battery cells need to be prepared as samples. These battery cells have different designs, materials, or manufacturing processes, but all are for studying the relationship between the weight and capacity of the battery cells.

[0125] In a laboratory environment, use precise equipment to measure the weight and capacity of each battery cell. The weight is usually measured by a balance, while the capacity can be obtained through a discharge test, that is, measuring the total amount of electricity that the battery cell can release under specific conditions.

[0126] (2) Obtain the capacities of multiple sample battery cells with different weights, and fit the battery cell capacity and the battery cell weight to obtain the relationship: y = Am + B, which is a linear relationship, where y is the battery cell capacity, m is the battery cell weight, and A and B are constants representing the slope and intercept of the change of the battery cell capacity with the weight;

[0127] It should be noted that after collecting the weight and capacity data of all battery cells, in this step, the battery cell capacity y is used as the dependent variable and the battery cell weight m is used as the independent variable for statistical analysis or data fitting.

[0128] (3) Obtain the capacities of multiple sample battery cells with the same weight, and calculate the mean value of the battery cell capacities to obtain D;

[0129] It should be noted that this step is to evaluate the variability of the battery cell capacity under the same weight and may be used as a benchmark or reference for subsequent analysis.

[0130] (4) Through the formula get , where ; ;

[0131] (5) Through the formula get to construct the relationship among the corrected capacity, the battery cell weight, and the battery cell capacity. Among them, is the corrected capacity, is the battery cell capacity, and c is the capacity compensation coefficient.

[0132] It should be noted that in this step, the goal is to obtain a corrected capacity relationship that can more accurately reflect the actual relationship between the battery cell weight and the capacity, while taking into account the variability between battery cells and other factors that may affect the capacity.

[0133] Although terms such as battery cells, capacitance values, and facing areas are used frequently in this application, the possibility of using other terms is not excluded. The use of these terms is only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

[0134] A battery capacity detection method provided by an embodiment of the present invention calculates the facing area between the positive electrode plate and the negative electrode plate in the battery cell through the capacitance value of the battery cell, and then calculates based on the facing area, so that the capacity of the battery cell can be finally determined. It can not only ensure high detection accuracy, but also greatly shorten the detection time because there is no need to charge and discharge the battery cell. At the same time, the detection cost is low, which is conducive to the wide production and popularization of the battery.

[0135] Embodiment Two

[0136] Please refer to Figure 4 , an embodiment two of the present invention provides a battery capacity detection system, which includes a capacitance detection module 201, an area calculation module 202, and a capacity calculation module 203;

[0137] The capacitance detection module 201 is used to detect the capacitance value of the battery cell;

[0138] The area calculation module is used to calculate and determine the facing area between the positive electrode plate and the negative electrode plate in the battery cell based on the capacitance value;

[0139] The capacity calculation module is used to:

[0140] Calculate and determine the calculated capacity of the battery cell based on the facing area.

[0141] It should be noted that the capacitance detection module 201 can be, for example, a high-precision capacitance test device to ensure the accuracy of the measurement results.

[0142] Preferably, the area calculation module 202 is specifically used to:

[0143] Obtain the dielectric constant of the medium between the positive electrode plate and the negative electrode plate in the battery cell; obtain the distance between the positive electrode plate and the negative electrode plate in the battery cell; and calculate and determine the facing area between the positive electrode plate and the negative electrode plate in the battery cell according to the following formula:

[0144] ;

[0145] Wherein, is the capacitance value of the battery cell; is the dielectric constant of the medium between the positive electrode plate and the negative electrode plate in the battery cell; is the facing area between the positive electrode plate and the negative electrode plate in the battery cell; is the electrostatic constant; is the distance between the positive electrode sheet and the negative electrode sheet in the battery cell.

[0146] Preferably, the capacity calculation module 203 is specifically configured to:

[0147] Obtain the coating surface density of the positive electrode sheet in the battery cell; and calculate and determine the calculated capacity of the battery cell according to the following formula:

[0148] ;

[0149] Wherein, is the calculated capacity of the battery cell; is the facing area between the positive electrode sheet and the negative electrode sheet in the battery cell; is the coating surface density of the positive electrode sheet in the battery cell.

[0150] It should be noted that the area calculation module 202 and the capacity calculation module 203 can be implemented by, for example, a computer or a dedicated processor with powerful computing and storage functions.

[0151] Preferably, the capacitance detection module 201 is specifically configured to:

[0152] Electrically connect a capacitance test device to the positive electrode tab and the negative electrode tab of the battery cell respectively, and then control the capacitance test device to work.

[0153] Preferably, the system further includes a capacity correction module for:

[0154] Based on the following relationship among the corrected capacity, the weight of the battery cell, and the calculated capacity, correct the calculated capacity to obtain the corrected capacity of the battery cell:

[0155] ;

[0156] Wherein, is the corrected capacity of the battery cell; is the calculated capacity of the battery cell; is the weight of the battery cell; , are constants; is the capacity compensation coefficient.

[0157] It should be noted that the weight of the battery cell can be measured, for example, using a high-precision weighing device such as an electronic scale or an electronic balance to ensure the accuracy of the weight data.

[0158] Preferably, the system further includes a relationship construction module for:

[0159] Prepare multiple sample battery cells and measure the weights and capacities of the battery cells in a laboratory environment;

[0160] Obtain the capacities of multiple sample battery cells with different weights, and fit the capacities and weights of the battery cells to obtain a relational expression: y = Am + B, where y is the capacity of the battery cell, m is the weight of the battery cell, and A and B are constants;

[0161] Obtain the capacities of multiple sample battery cells with the same weight, and calculate the average value of the capacities to obtain D;

[0162] Through the formula get , where , ;

[0163] Through the formula get , so as to construct a relational expression among the corrected capacity, the weight of the battery cell, and the capacity of the battery cell. Among them, is the corrected capacity, is the capacity of the battery cell, and c is the capacity compensation coefficient.

[0164] A battery capacity detection system provided by an embodiment of the present invention can detect the capacitance value of a battery cell, then calculate the facing area between the positive electrode plate and the negative electrode plate in the battery cell based on the capacitance value, and then calculate based on the facing area, so that the capacity of the battery cell can be finally determined. It can not only ensure high detection accuracy, but also greatly shorten the detection time because there is no need to charge and discharge the battery cell. At the same time, the detection cost is low, which is beneficial to the extensive production and popularization of batteries.

[0165] The above system can execute the method provided by any embodiment of the present invention, and has corresponding functional modules and beneficial effects for executing the method.

[0166] Embodiment III

[0167] Figure 5 It is a schematic structural diagram of a computer device provided by Embodiment III of the present invention. Figure 5 It shows a block diagram of an exemplary computer device 12 suitable for implementing the embodiments of the present invention. Figure 5 The shown computer device 12 is only an example and should not impose any limitation on the functions and usage scope of the embodiments of the present invention.

[0168] As Figure 5 shown, the computer device 12 is presented in the form of a general-purpose computing device. The components of the computer device 12 may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 connecting different system components (including the system memory 28 and the processing unit 16).

[0169] Bus 18 represents one or more of several types of bus architectures, including a memory bus or memory controller, a peripheral bus, an Accelerated Graphics Port, a processor bus, or a local bus using any of a variety of bus architectures. By way of example, and not limitation, these architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, Enhanced ISA bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus.

[0170] Computer device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by computer device 12, including both volatile and nonvolatile media, removable and non-removable media.

[0171] System memory 28 can include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. Computer device 12 can further include other removable / non-removable, volatile / nonvolatile computer system storage media. By way of example only, storage system 34 can be used for reading from and writing to non-removable, nonvolatile magnetic media ( Figure 5 not shown and typically called a "hard disk drive"). Although Figure 5 not shown in the figures, a disk drive for reading from and writing to a removable nonvolatile disk (e.g., a "floppy disk"), and an optical disk drive for reading from and writing to a removable nonvolatile optical disk (e.g., a CD-ROM, a DVD-ROM, or other optical media) can be provided. In these instances, each drive can be connected to bus 18 by one or more data media interfaces. Memory 28 can include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the present invention.

[0172] A program / utility 40 having a set (at least one) of program modules 42 can be stored, for example, in memory 28, such program modules 42 including, but not limited to, an operating system, one or more application programs, other program modules, and program data, each of which examples or some combination thereof may include an implementation of a network environment. The program modules 42 typically carry out the functions and / or methods of the embodiments described herein.

[0173] The computer device 12 can also communicate with one or more external devices 14 (such as a keyboard, a pointing device, a display 24, etc.), and can also communicate with one or more devices that enable a user to interact with the computer device 12, and / or communicate with any device that enables the computer device 12 to communicate with one or more other computing devices (such as a network card, a modem, etc.). Such communication can be carried out through the input / output (I / O) interface 22. Moreover, the computer device 12 can also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through the network adapter 20. As shown in the figure, the network adapter 20 communicates with other modules of the computer device 12 through the bus 18. It should be understood that although Figure 5 not shown in the figure, other hardware and / or software modules can be used in combination with the computer device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, etc.

[0174] The processing unit 16 executes various functional applications and data processing by running programs stored in the system memory 28, such as implementing the battery capacity detection method provided by the embodiments of the present invention.

[0175] Finally, it should be noted that although the above embodiments have been described in the text and drawings of the specification of the present application, the patent protection scope of the present application cannot be limited thereby. Any technical solutions obtained by equivalent structure or equivalent process substitution or modification based on the substantial concept of the present application, using the content recorded in the text and drawings of the specification of the present application, and any technical solutions directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, etc., are all included in the patent protection scope of the present application.

Claims

1. A battery capacity detection method, characterized in that: The method comprises: Detect the capacitance value of the battery cell; Determine the facing area of ​​the positive electrode sheet and the negative electrode sheet in the battery cell based on the capacitance value; The calculated capacity of the battery cell is determined based on the facing area.

2. The battery capacity detection method according to claim 1, characterized in that: The step of calculating and determining the facing area of ​​the positive electrode sheet and the negative electrode sheet in the battery cell based on the capacitance value includes: Obtain the dielectric constant of the medium between the positive electrode sheet and the negative electrode sheet in the battery cell; obtain the distance between the positive electrode sheet and the negative electrode sheet in the battery cell; and calculate and determine the facing area of ​​the positive electrode sheet and the negative electrode sheet in the battery cell according to the following formula: ； in, is the capacitance value of the battery cell; is the dielectric constant of the medium between the positive electrode sheet and the negative electrode sheet in the battery cell; is the facing area of ​​the positive electrode sheet and the negative electrode sheet in the battery cell; is the electrostatic force constant; is the distance between the positive electrode sheet and the negative electrode sheet in the battery cell.

3. The battery capacity detection method according to claim 1, characterized in that: The step of calculating and determining the calculated capacity of the battery cell based on the facing area includes: Obtain the coating surface density of the positive electrode sheet in the battery cell; and calculate and determine the calculated capacity of the battery cell according to the following formula: ； in, is the calculated capacity of the battery cell; is the facing area of ​​the positive electrode sheet and the negative electrode sheet in the battery cell; is the coating surface density of the positive electrode sheet in the battery cell.

4. The battery capacity detection method according to claim 1, characterized in that: The steps for detecting the capacitance value of the battery cell include: Make the capacitor testing device electrically connected to the positive and negative ears of the battery cell respectively, and then control the capacitor testing device to work.

5. The battery capacity detection method according to any one of claims 1 to 4, characterized in that: The method further comprises: The calculated capacity is corrected based on the following relationship among the corrected capacity, the cell weight and the calculated capacity to obtain the corrected capacity of the cell: ； in, is the corrected capacity of the battery cell, is the calculated capacity of the battery cell, m is the weight of the battery cell, a and b are constants, and c is the capacity compensation coefficient.

6. The battery capacity detection method according to claim 5, characterized in that: The method further comprises: Prepare multiple sample cells and measure the cell weight and cell capacity in a laboratory environment; Obtain the cell capacities corresponding to multiple sample cells with different cell weights, and fit the cell capacities and cell weights to obtain the relationship: y=Am+B, where y is the cell capacity, m is the cell weight, and A and B are constants; Obtain the cell capacities corresponding to multiple sample cells with the same cell weight, and calculate the average of the cell capacities to obtain D; By formula get, ,in, , ; By formula get, , in order to construct the relationship between the corrected capacity, cell weight and cell capacity, where: To correct the capacity, is the cell capacity, and c is the capacity compensation coefficient.

7. A battery capacity detection system, characterized in that: The system includes a capacitance detection module, an area calculation module and a capacity calculation module; The capacitance detection module is used to detect the capacitance value of the battery cell; The area calculation module is used to calculate and determine the facing area of ​​the positive electrode sheet and the negative electrode sheet in the battery cell based on the capacitance value; The capacity calculation module is used for: The calculated capacity of the battery cell is determined based on the facing area.

8. The battery capacity detection system according to claim 7, characterized in that: The area calculation module is specifically used for: Obtain the dielectric constant of the medium between the positive electrode sheet and the negative electrode sheet in the battery cell; obtain the distance between the positive electrode sheet and the negative electrode sheet in the battery cell; and calculate and determine the facing area of ​​the positive electrode sheet and the negative electrode sheet in the battery cell according to the following formula: ； in, is the capacitance value of the battery cell; is the dielectric constant of the medium between the positive electrode sheet and the negative electrode sheet in the battery cell; is the facing area of ​​the positive electrode sheet and the negative electrode sheet in the battery cell; is the electrostatic force constant; is the distance between the positive electrode sheet and the negative electrode sheet in the battery cell; The capacity calculation module is specifically used for: Obtain the coating surface density of the positive electrode sheet in the battery cell; and calculate and determine the calculated capacity of the battery cell according to the following formula: ； in, is the calculated capacity of the battery cell; is the facing area of ​​the positive electrode sheet and the negative electrode sheet in the battery cell; is the coating surface density of the positive electrode sheet in the battery cell.

9. The battery capacity detection system according to claim 7, characterized in that: The system further comprises a capacity correction module, for: The calculated capacity is corrected based on the following relationship among the corrected capacity, the cell weight and the calculated capacity to obtain the corrected capacity of the cell: ； in, is the corrected capacity of the battery cell; is the calculated capacity of the battery cell; is the weight of the battery cell; , is a constant; is the capacity compensation factor.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the battery capacity detection method according to any one of claims 1 to 6 is implemented.

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